2Quantum Numbers PRINCIPAL: n energy level, the distance the orbital is from the nucleus(1, 2, 3, 4…)ANGULAR MOMENTUM: l shape(s = 0, p = 1, d = 2, f = 3)MAGNETIC: ml spatial orientation(0 for s; -1, 0, +1 for p; -2, -1, 0, +1, +2 for d, etc.)SPIN: ms spin (+1/2 or -1/2)
3Review Atomic number = # electrons Electrons occupy orbitals defined by n, l, mEach orbital can hold two electronsOrbitals diffuse electron cloud“lower energy electron” closer to nucleusOuter electrons: “valence” most reactive
4Quantum Numbers The principal quantum number has the symbol n. n = 1, 2, 3, 4, “shells”(n = K, L, M, N, )The electron’s energy depends principally on n .
5Quantum Numbers The angular momentum quantum number has the symbol . = s, p, d, f, g, h, (n-1) tells us the shape of the orbitals.These orbitals are the volume around the atom that the electrons occupy 90-95% of the time.
6Quantum NumbersThe symbol for the magnetic quantum number is m, representing the spatial orientation.m = - , (- + 1), (- +2), , , ( -2), ( -1), If = 0 (or an s orbital), then m = 0.If = 1 (or a p orbital), then m = -1,0,+1.yzx
7If = 2 (or a d orbital), then m = -2,-1,0,+1,+2. If = 3 (or an f orbital), then m = -3,-2,-1,0,+1,+2, +3.Theoretically, this series continues on to g,h,i, etc
8Spin quantum numberThe last quantum number is the spin quantum number which has the symbol ms.The spin quantum number only has two possible values.ms = +1/2 or -1/2
10Spin quantum number effects: Every orbital can hold up to two electrons.Consequence of the Pauli Exclusion Principle.The two electrons are designated as havingone spin up and one spin downSpin describes the direction of the electron’s magnetic fields.
11Re-Cap: Quantum Numbers PRINCIPAL: n energy level, distance from nucleus (1, 2, 3, 4…)ANGULAR MOMENTUM: l shape(s = 0, p = 1, d = 2, f = 3)MAGNETIC: ml spatial orientation(0 for s; -1, 0, +1 for p; -2, -1, 0, +1, +2 for d, etc.)SPIN: ms spin (+1/2 or -1/2)
12Atomic Orbitals: s, p, d, fAtomic orbitals are regions of space where the probability of finding an electron about an atom is highest.s orbital properties:There is one s orbital per n level. = 0 and only one value of m = 0
13s orbitals are spherically symmetric For every s orbital:= 0 and ml = 0The only thing that changes for s orbitals is n.
17p orbitals p orbital properties: The first p orbitals appear in the n = 2 shell.p orbitals are peanut or dumbbell shaped volumes.There are 3 p orbitals per n level.The three orbitals are named px, py, pz. = 1 for all p orbitals.m = -1,0,+1 (designate the three orientations)
21d orbital properties: The five d orbitals have two different shapes: The first d orbitals appear in the n = 3 shell.The five d orbitals have two different shapes:4 are clover leaf shaped.1 is peanut shaped with a doughnut around it.The orbitals lie directly on the Cartesian axes or are rotated 45o from the axes.There are 5 d orbitals per n level.The five orbitals are named:They have an = 2.m = -2,-1,0,+1,+2 (5 values of m )
24f orbital properties: The f orbitals have the most complex shapes. The first f orbitals appear in the n = 4 shell.The f orbitals have the most complex shapes.There are seven f orbitals per n level.The f orbitals have complicated names.They have an = 3m = -3,-2,-1,0,+1,+2, values
27Quantum NumbersPRINCIPAL: n energy level, distance from orbital (1, 2, 3, 4…)ANGULAR MOMENTUM: l shape(s = 0, p = 1, d = 2, f = 3)MAGNETIC: ml spatial orientation(0 for s; -1, 0, +1 for p; -2, -1, 0, +1, +2 for d, etc.)SPIN: ms spin (+1/2 or -1/2)
49Or you can use the periodic chart . 123456GeGe = 1s22s22p63s23p64s23d104p2or [Ar] 4s23d104p2or [Ar]3d10 4s24p2
50Hund’s rule tells us that the electrons will fill the p orbitals by placing electrons in each orbitalsingly and with same spin until half-filled. Thenthe electrons will pair to finish the p orbitals.